Something from SWR, like a Workingman's combo, or one of their new series budget combos. Fender Bassman 25 (probably the one I would choose... great tone, only about $10 more than the low-end SWR, and lots of cool features for a little 10" combo). Small Ampeg combos are nice, but even then you're already getting bigger and more expensive. I would go with the Fender, it can be had for around $400 I think, and it's a great little amp. This is, of course, just a starting place, as I'm sure others will have LOTS more suggestions. Also, look into used gear. You can usually get NICE deals on some good gear. Just shop around and try things out to see if you like them.

ciao dino! i saw that you are from italy too! that's great. i highly suggest the fender bassman 25. but to be honest i ended buying a EKO XB30v. that's a good practice amp i use daily. not the best but for the price it's really good sounding, much better than the peavey. the only bad thing is that the onboard compressor is totally useless. otherwise really good sound. i paid 300.000£ ooops, 150 euro!